This invention relates to a method and an apparatus for attaching a lid member of automobile, particularly, a method and an apparatus for attaching a lid member, such as a bonnet, a truck lid or the like, to the specified position of a car body.
Generally, a lid member such as a bonnet, a trunk lid or the like, is attached at a metal line process (where metal parts, such as doors, a front fender or the like are attached) to a car body which was assembled at a floor main process and a main body assembling process.
Usually, the lid member mentioned above is attached to the car body in the following way. The lid member is set manually, in its opened state, to the attaching position at an opening of the car body. Then, a hinge member fixed to the specified position of the lid member is located to a hinge attaching part of the car body and is fastened by bolts. However, since a lid member such as a bonnet is comparatively heavy in weight, attaching of it to the car body has been an intricate work.
For the purpose of automating the lid member attaching work, Japanese Utility Model Registration Application Laying Open Gazette No. 56-28826, for example, disclosed a lid member attaching apparatus provided with a stocker which stocks a plurality of lid members, a conveying device which takes out lid members one by one from said stocker and conveys each lid member to the specified position, a transferring and locating device which transfers a lid member carried to the specified position to the attaching position at an opening of the car body and sets it there and a fastening device which fastens a hinge member fixed beforehand to the car body to the located lid member.
Recently, for the purpose of automating the bonnet attaching work, Japanese Patent Application Laying Open Gazette No. 62-99272, for example, has disclosed a robot for attaching a bonnet, whereby the position of a hinge attaching part is detected accurately by measuring a datum point provided in the car body, on the basis of such detected data a bonnet held by an adsorption pad, for example, is transferred, in its opened state, to the specified position of the car body, and a hinge member is located to a hinge attaching part.
In the case of the above-mentioned robot for attaching a bonnet, since a bonnet is transferred, in its opened state, to the specified position of the car body, a hinge member to be fastened to the car body side is also held in an opened state by its own weight, namely, is held in a sitting posture in relation to the hinge attaching part of the car body and therefore the hinge member can easily be seated on the hinge attaching part by moving the bonnet downward, without the necessity of changing the hinge member to a sitting posture.
However, in the above robot for attaching a bonnet, since a bonnet is transferred, in its opened state, to the specified position of the car body, when the bonnet is put in a closed state after the hinge member was fastened by a bolt, the bonnet is not held at the proper position due to manufacturing errors of the hinge member and attaching errors of the hinge member in relation to the bonnet and the car body, namely, clearances between the bonnet and the right/left fender are not uniformed. This spoils external appearance of the automobile and causes such problem that the side of the bonnet interfers with the fender.
On the other hand, it can be taken into consideration to attach a bonnet, in its closed state, to the car body. For example, in the case where each of plural locating pins is inserted in a respective locating hole made in the bonnet for locating the bonnet in relation to the car body, for example, if it is tried to improve positional precision of the locating pin and the locating hole for the purpose of improving the bonnet attaching precision, bad insertion of the locating pin can be caused due to positional errors of the locating pins and positional errors of the locating holes.